src/basic/fs-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 #include <dirent.h>
   5 #include <fcntl.h>
   6 #include <limits.h>
   7 #include <stdbool.h>
   8 #include <stdint.h>
   9 #include <sys/inotify.h>
  10 #include <sys/stat.h>
  11 #include <sys/types.h>
  12 #include <unistd.h>
  13
  14 #include "errno-util.h"
  15 #include "time-util.h"
  16
  17 int unlink_noerrno(const char *path);
  18
  19 int rmdir_parents(const char *path, const char *stop);
  20
  21 int rename_noreplace(int olddirfd, const char *oldpath, int newdirfd, const char *newpath);
  22
  23 int readlinkat_malloc(int fd, const char *p, char **ret);
  24 int readlink_malloc(const char *p, char **r);
  25 int readlink_value(const char *p, char **ret);
  26 int readlink_and_make_absolute(const char *p, char **r);
  27
  28 int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid);
  29 int fchmod_and_chown(int fd, mode_t mode, uid_t uid, gid_t gid);
  30
  31 int fchmod_umask(int fd, mode_t mode);
  32 int fchmod_opath(int fd, mode_t m);
  33
  34 int fd_warn_permissions(const char *path, int fd);
  35
  36 #define laccess(path, mode) faccessat(AT_FDCWD, (path), (mode), AT_SYMLINK_NOFOLLOW)
  37
  38 int touch_file(const char *path, bool parents, usec_t stamp, uid_t uid, gid_t gid, mode_t mode);
  39 int touch(const char *path);
  40
  41 int symlink_idempotent(const char *from, const char *to, bool make_relative);
  42
  43 int symlink_atomic(const char *from, const char *to);
  44 int mknod_atomic(const char *path, mode_t mode, dev_t dev);
  45 int mkfifo_atomic(const char *path, mode_t mode);
  46 int mkfifoat_atomic(int dir_fd, const char *path, mode_t mode);
  47
  48 int get_files_in_directory(const char *path, char ***list);
  49
  50 int tmp_dir(const char **ret);
  51 int var_tmp_dir(const char **ret);
  52
  53 int unlink_or_warn(const char *filename);
  54
  55 #define INOTIFY_EVENT_MAX (sizeof(struct inotify_event) + NAME_MAX + 1)
  56
  57 #define FOREACH_INOTIFY_EVENT(e, buffer, sz) \
  58         for ((e) = &buffer.ev;                                \
  59              (uint8_t*) (e) < (uint8_t*) (buffer.raw) + (sz); \
  60              (e) = (struct inotify_event*) ((uint8_t*) (e) + sizeof(struct inotify_event) + (e)->len))
  61
  62 union inotify_event_buffer {
  63         struct inotify_event ev;
  64         uint8_t raw[INOTIFY_EVENT_MAX];
  65 };
  66
  67 int inotify_add_watch_fd(int fd, int what, uint32_t mask);
  68
  69 enum {
  70         CHASE_PREFIX_ROOT = 1 << 0, /* If set, the specified path will be prefixed by the specified root before beginning the iteration */
  71         CHASE_NONEXISTENT = 1 << 1, /* If set, it's OK if the path doesn't actually exist. */
  72         CHASE_NO_AUTOFS   = 1 << 2, /* If set, return -EREMOTE if autofs mount point found */
  73         CHASE_SAFE        = 1 << 3, /* If set, return EPERM if we ever traverse from unprivileged to privileged files or directories */
  74         CHASE_OPEN        = 1 << 4, /* If set, return an O_PATH object to the final component */
  75         CHASE_TRAIL_SLASH = 1 << 5, /* If set, any trailing slash will be preserved */
  76         CHASE_STEP        = 1 << 6, /* If set, just execute a single step of the normalization */
  77         CHASE_NOFOLLOW    = 1 << 7, /* Only valid with CHASE_OPEN: when the path's right-most component refers to symlink return O_PATH fd of the symlink, rather than following it. */
  78         CHASE_WARN        = 1 << 8, /* Emit an appropriate warning when an error is encountered */
  79 };
  80
  81 /* How many iterations to execute before returning -ELOOP */
  82 #define CHASE_SYMLINKS_MAX 32
  83
  84 int chase_symlinks(const char *path_with_prefix, const char *root, unsigned flags, char **ret);
  85
  86 int chase_symlinks_and_open(const char *path, const char *root, unsigned chase_flags, int open_flags, char **ret_path);
  87 int chase_symlinks_and_opendir(const char *path, const char *root, unsigned chase_flags, char **ret_path, DIR **ret_dir);
  88 int chase_symlinks_and_stat(const char *path, const char *root, unsigned chase_flags, char **ret_path, struct stat *ret_stat);
  89
  90 /* Useful for usage with _cleanup_(), removes a directory and frees the pointer */
  91 static inline void rmdir_and_free(char *p) {
  92         PROTECT_ERRNO;
  93         (void) rmdir(p);
  94         free(p);
  95 }
  96 DEFINE_TRIVIAL_CLEANUP_FUNC(char*, rmdir_and_free);
  97
  98 static inline void unlink_and_free(char *p) {
  99         (void) unlink_noerrno(p);
 100         free(p);
 101 }
 102 DEFINE_TRIVIAL_CLEANUP_FUNC(char*, unlink_and_free);
 103
 104 int access_fd(int fd, int mode);
 105
 106 void unlink_tempfilep(char (*p)[]);
 107 int unlinkat_deallocate(int fd, const char *name, int flags);
 108
 109 int fsync_directory_of_file(int fd);
 110 int fsync_path_at(int at_fd, const char *path);
 111
 112 int syncfs_path(int atfd, const char *path);
 113
 114 int open_parent(const char *path, int flags, mode_t mode);